Jon,
I think you are talking about the .25 WSSM. As was stated, this is a shorter version of the the WSM, hence the name Winchester SUPER Short Magnum.
Yes, it does duplicate the ballistics of a .25-06, but in a shorter and fatter case.
I'm not too crazy about this particular round. I would be much more interested if it were a 25 WSM, so that it would be faster than a .25-06, and perhaps almost as fast as a .257 Weatherby.
I don't think that this round is going to last very long, and it certainly won't have the availability in both ammo and rifles as the .25-06.
Zachary